Limit switch actuator



Jan. 21, 1969 J. E. AcoRD 3,423,554

LIMIT SWITCH ACTUATOR Filed June 27, 1966 fer 5, ,4502.0

' f7/MX 95x,

United States Patent G 2 Claims ABSTRACT F THE DISCLOSURE Self-contained mounting means adapted to have a push button type switch mounted therein, the mounting means adapted to be mounted on a plane surface of any structure. The mounting means includes a bore and embodies means insuring that the switch will be energized and deenergized merely by inserting an article by cylindrical configuration in and removing the article from the bore.

This invention relates :generally to actuators for electrical switches and more particularly to a self-contained actuator adapted to actuate an electrical switch of a sensitive type mounted therein and embodying means whereby the switch may be activated or deactivated quickly, safely and positively without damage to the switch.

The term sensitive switch or sensitive switches as used through this specification and appended claims refers to electrical switches requiring minimum movements only of the actuator button. to effect the actuation thereof. In other words the operating characteristics of switches of the above type are such that movement of the switches actuator button is restricted to ranges of small magnirude-for example, ranges of approximately five to ten thousands of an inch (.005.()l0").

The switch actuator as disclosed herein is specifically designed to render a tire control circuit or the like of a military plane inoperative at such times as the plane is on the ground and at rest, however, the present actuator may be utilized to interrupt and subsequently close any circuit under similar conditions requiring the quick and positive operation of a sensitive switch without danger of damage to the switch associated with the actuator.

During a turn around phase of military aircraft it is desirable (in fact mandatory) that the tire control circuits thereof be rendered inoperative. This action is taken as a precautionary measure so that the plane may safely be rearmed without danger of accidently closing a tire control circuit resulting in firing the planes armament. This operation is performed by the ground crews and quite frequently has to be expedited.

A disarming operation of the above type is normally effected from outside the aircraft utilizing a device having a visual signal attached thereto. The device utilized normally constitutes a pin or rod member positioned in aligned apertures provided in fixed structure of the aircraft, the switch is also secured to the same fixed structure of the aircraft. If these apertures, consequently the pin or rod member inserted therein, do not have the correct relationship with respect to the switch being actuated or vice versa, it becomes apparent that the switch, in being actuated in the manner described above, may be damaged or rendered inoperative.

Accordingly it is a principal object of the present invention to disclose an actuator adapted to have a sensitive type electrical switch mounted therein, the actuator insuring quick and positive actuation of a switch mounted therein and precluding the possibility of damage thereto.

Another object is to disclose an actuator adapted to have a sensitive type electrical switch mounted therein ICC which is secured internally of structure and is operable externally of the structure.

Another object is to disclose an actuator adapted to have a sensitive type electrical switch mounted therein which is quickly and easily attached to supporting structure as a single component.

Another object is to disclose an actuator adapted to have a sensitive switch mounted therein that is of rugged construction, economical to manufacture, presents a minimum of mal-functioning tendencies and is easier to install than presently known actuators.

Although the characteristic features of the present invention are particularly ipointed out in the appended claims, the invention itself, also the manner in which it may be carried out, will be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of this application and in which:

FIGURE l is a iside of the actuator as disclosed herein having a sensitive type electrical switch mounted therein.

FIGURE 2 constitutes an exploded view in perspective of the actuator and switch of FIGURE l.

Referring to the drawing, FIGURE yl `shows an actuator mechanism 11-as disclosed herein-having a sensitive type electrical switch member 12 mounted therein. In the present application, the mechanism 11 and `switch 12 are discussed as being utilized to render a tire control circuit of a military aircraft inoperative, however, it should be understood that the mechanism 11 and switch 12 may be used in any situation under similar conditions.

The mechanism 11 includes a bracket or mounting member and a spring member 14 and 16, respectively, as best seen in FIGURE 2, having the aforementioned switch member 12 mounted therein.

The switch 12, referred to as a sensitive switch, is of conventional design requiring slight movements only of its actuator button to activate or deactivate the switch member. In view of the nature of the switch 12 and operating principle thereof further discussion in this respect is not believed necessary.

The mounting member 14 is generally T-shaped including arm and leg portions 17 `and 18, respectively. The leg and arm portions 17 and 18 are generally square or rectangular in cross-section having a web 19 provided between the portion 18 and one of the portions 17, substantially as shown in FIGURE 2. The yweb portion 19 provides means for securing the switch 12 to the member 14 and a pair of apertures 21 is provided for this purpose.

A `cylindrical passageway 22 is` provided extending longitiudinally throughout the extent of the leg portion 18,

the axis of the passageway 22 and the axis of the leg portion 18 coincide as indicated by the line A-A in FIGURES 1 and 2. A passageway 23 is provided in each of the arm portions 17 adapted to receive rivets 24 providing means whereby the member 14 may be secured to structure 26 fof an aircraft (not show-n). The leg portion 18, adjacent the web portion 19, defines an arcuate surface 27 having generally a tangential relation with rcspect to the axes A--A of the passageway 22. Positioned in this manner, the intersection of the surface 27 with the passageway 22 denes an elliptical-like opening providing a function more fully discussed as the disclosure progresses.

The spring member 16 includes rigid and resilient portions 28 and 31, respectively. The portion 28 of the member 16 carries a couple of apertures 32, the latter providing means for mounting the spring 16 on the member 14. The resilient portion 31 constitutes a leaf spring substantially of the salme width as the member 14 and includes an arcuate portion indicated by the numeral 33.

In the assembled relation of the members 14, 16 and 12, bolt members 35 are received in apertures 32 and 21 and provide means for securing the switch 12 and spring member 16 on the member 14. Also in the assembled relation of the members 14 and 16, the arcuate portion 33 of the spring is shaped to mate with the surface 27 of the member 14 and completely closes the aforementioned elliptical-like opening formed by the intersection of the surface 27 with the passageway 22. The outer end of the spring portion 31 is shaped substantially as shown in FIGURES 1 and 2.

Refering further to the assembled relation of the switch, the resilient spring portion 31 has an active and inactive position as show-n in dotted and solid construction lines, respectively, in FIGURE l.

The resilient portion 31 of the spring member 16 is urged from its inactive to its active position by a rod or pin member 3'4 which is inserted in the passageway 22 and beyond the resilient portion 31 of the spring 16. A flag or streamer (not shown) -norrnally red--is secured to the outer end of the pin member 34.

The pin member 34 is inserted in the passageway 22 from a posiiton outside the structure 26 which in the present embodiment may represent the skin of an airplane. Inasmuch as the switch 12 and mounting member 14, also the spring member 16 (with exception of small movements imparted to the portion 31 of the spring by the pin member 34) have the same relation at all times, it will be apparent that the actuator button of the switch 12 will be depressed the same amount each time the pin member 34 'is inserted in the passageway 22. It will also be apparent that the switch 12 will be actuated and a lire control circuit (not shown) activated at such time fas the pin member 34 is in position and remain so until the pin member is removed from the passageway 22. Also it will be seen that the opening provided by the intersection of the surface 27 and the passageway 22 is completely closed at such time as the portion 31 of the spring member is in its inactive position.

Accordingly it will be seen that the pin 34 imparts identical movements to the switch 12 each time the pin 34 is frully inserted in the passageway 22, also the mechanism 11 provides the other objects of the invention as set out herein.

While in order to comply with the statute, the invention has been described in language more or less specic as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed cornprise the preferred form of putting the invention into eifect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

I claim:

1. A self-contained mounting member adapted to have a push button switch mounted therein and including means for yactuating the same, comprising:

(a) a mounting member including primary and secondary portions, the primary portion being generally of T-shaped conguration including arm and leg portions;

(b) said arm portions including means whereby the mounting member may be secured to a plane surface of any structure;

(c) said leg portion dening a bore extending longitudinally thereof and also a cavity the inner surface of which is of arcuate configuration having generally la tangential relation with the axis of said bore;

(d) spring means including rigid and resilient portions,

the latter portion constituting a leaf-type spring having the same configuration as the inner surface of said cavity;

(e) means securing said spring means to said secondary portion in a manner in which major or portions of the resilient portion of said spring means has a 'contacting relation with respect to said inner surface;

(f) and said secondary portion providing means whereby a push button type switch may be mounted thereon and the button of the switch being depressed by said resilient portion in response to a cylindrical member being urged into and substantially throughout the extent of said bore.

2. Apparatus as set forth in claim 1:

(a) in which said mounting means is constructed of a dielectric material and the resilient portion of said spring means completely covers the opening between the inner wall of said cavity and said bore.

References Cited UNITED STATES PATENTS 2,040,214 5/1936- Ramirez et al 20G-61.59 2,375,393 5/1945 Story 20D-61.59 2,584,390 2/1952 Lauder 20G- 153.12 X

ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner.

U.S. Cl. X.R. ZOO- 51.09, 61.59 

